I’ve done this with my first rental 25 years ago and they destroyed the house causing me to give up real estate for 20 years which was the biggest mistake ever and the only thing in my life I truly regret.

In assembling complete guidelines and cheat sheets of investor programs, products and incentives for an internal investor resource guide, I can tell you that as much as things have evolved when it comes to mortgage lending since 2008, not that much has changed. 

The biggest reason to go DSCR versus second home would likely be qualifications.

Would you buy many SFH's or would you by a few 2-4 unit MFH's or would you go for the big one and use all $500k as a down payment towards the biggest MFH you could find that you qualified for? 

Biggest regret was waiting to long to hire a property mgr.

SOI was the biggest way to gain clients. 

That's my understanding as well, which again brings me back to what is the incentive to sign you up even for just that house?

Another thought - When purchasing HVACs, roofs, tree removal, siding, etc. you can very easily pay "retail" (just look for the biggest ad campaigns online) or you can save 30-50% by being your own GC and finding or going to the crews directly.

Biggest myths#1 Cash flow matters most or appreciation is not important.   

Once the closing takes place, the seller has zero incentive to cooperate with supplying them.